Industrial cleaning has long been a dirty business. Degreasers and solvents, which are used to clean manufacturing equipment, can cause long-term contamination of water and soil, and can potentially lead to severe problems of ecological and public health. Part of moving towards a sustainable society means asking whether using these harmful chemicals is even necessary—and developing substitute products to make sure that it is not. In the case of industrial cleaning, promising new research from a Swedish university suggests an alternative may soon be available: 'ultra-clean' water.

Ultra-clean water is produced using an advanced filtering system that removes salt, minerals, lime, heavy metals, and other byproducts. After filtration, high surface tension at the molecular level gives the water the ability to powerfully dissolve dirt. After being used to clean greasy parts, the water can be refiltered and then used to clean again, in a closed cycle. Manufacturers could also choose to filter the water and emit it into the sewage system without the usual discharge of hazardous chemicals. The process uses cold rather than hot water, increasing its energy efficiency.

The Swedish company Servicestaden already uses ultra-clean water to clean building exteriors and road tunnels. After seeing the potential opportunity for the product in the manufacturing industry—which already faces increased regulation of chemical use--Servicestaden began working with researchers at Linköping University to speed technological development.

Although the technique is effective in cleaning, it is not yet ready for full implementation. One challenge is time: the process of using ultra-clean water is currently much more time-intensive than conventional techniques, making the product impractical for widespread use in most manufacturing plants. Scientists are working on ways to improve performance. Research is currently in the prototyping phase, and the product should be commercially available to manufacturers by the end of 2009.

Adele Peters is currently earning a Master's in Sustainability at Blekinge Institute of Technology in Karlskrona, Sweden.

Images courtesy of Erik Sundin.

The idea of reusing water in the industrial cleaning process is a great way to make good use of water. I know that some industries are putting dirty waste water directly into rivers.

Posted by: Don Ross on 7 Nov 08

This is great. I wonder what the cost effectiveness will be under a (hopefully) future, fuller implementation of the technology. And what about the other side of the equation? Maybe the equivalent to molecular-level surface tension alterations in the greasing products (or greasy by-products) would help, too?